Coverings for architectural openings, such as windows, doors, archways, and the like, have taken numerous forms for many years. Some coverings include a retractable shade member that is movable between an extended position and a retracted position. A movable rail typically is attached to an edge of the shade member to facilitate extension of the shade member across the opening and to maintain the shade member in a taut configuration. Some shade members apply an asymmetric force to the rail, which tends to rotate the rail about its longitudinal axis, about an axis that is orthogonal to its longitudinal axis and to the plane of the shade member, or both.